This invention belongs to the field of agricultural chemistry, and provides to the art new herbicides and herbicidal methods.
It has long been established that herbicides are necessary to the most economical and productive use of the land. Herbicides are in demand for use in killing and controlling weeds growing in cropland, and also for killing and controlling unwanted vegetation of all kinds, such as in fallow land and on industrial property.
Despite the great amount of research effort which has been expended in agricultural chemistry, herbicides closely related to the compounds of this invention have not been previously discovered. The polyhalopyridinones, which have two or more chloride atoms as well as other alkyl and halo substituents on the pyridine rings, are known herbicides, but are obviously quite distant from the present invention.
Organic chemists have explored the piperidinones and dihydropyridinones to a degree. For example, Leonard et al., J. Am. Chem. Soc. 79, 156-60 (1957), disclosed 3,5-di(substituted-benzyl and benzylidene)-4-piperidinones, which are not herbicides.
Settimj et al. have worked with piperidinones, and have disclosed the unsubstituted 3,5-diphenyl-1-methyl-4-piperidione. Gazz. Chim. Ital. 96, 604-11 (1966), C.A. 65, 8913g (1966); Gazz. Chim. Ital. 96, 311-24 (1966), C.A. 67, 64261b (1967); Gazz. Chim. Ital. 100, 703-25 (1970), C.A. 74, 41752t (1971).